1. Field of the Invention
The present invention relates to a foam-type hair dye which is converted to foam by the blending of gas (air from outside the container, or compressed gas from inside of the container, for example) during use, to an application method for foam-type hair dye, and to a foam-type hair dye discharge apparatus.
2. Related Art of the Invention
In conventional practice, foam-type hair dye is used because of handling considerations related to minimal fluid dripping and the ease of achieving thin and even application.
Examples of discharge apparatuses for foam-type hair dye include hand foamers in which a liquid hair dye is stored in a container at normal pressure and is discharged from a discharge nozzle provided with a mesh using a pump mechanism, and devices for discharging liquid hair dye from a nozzle provided with a mesh using a squeeze container. There are also devices which use aerosol containers wherein LPG, nitrogen gas, or another propellant is stored together with liquid hair dye in a pressure-resistant container, and is then released.
However, conventional foam-type hair dye discharge apparatuses that use a normal-pressure container have a drawback in that agents unstable with regard to air cannot be stored over a long period of time, and cannot be used in air oxidation hair dyes in particular. Because foam is difficult to form in a hand foamer or other normal-pressure container when the liquid hair dye has high viscosity, the viscosity of the liquid hair dye is normally set to 100 mPa·s or less, resulting in fluid dripping, prolonged discharge time, and other drawbacks.
There are other problems in foam-type hair dye discharge apparatuses that use aerosol containers in that there are restrictions in the combination of propellants and liquid hair dye, the specific volume of the foam (foam-type hair dye volume/foam-type hair dye weight) is commonly high at 10 mL/g or more, and application is difficult.